1. Field
Exemplary embodiments of the present disclosure relate to an image forming apparatus, such as a copier, a printer, a facsimile machine, or a multifunctional device having at least two of the foregoing capabilities, and a fixing device employed in the image forming apparatus.
2. Description of the Background Art
Related-art image forming apparatuses, such as copiers, facsimile machines, printers, or multifunction apparatuses having at least one of copying, printing, scanning, and facsimile functions, typically form an image on a recording medium according to image data. Thus, for example, a charger uniformly charges a surface of an image carrier; an optical writer emits a light beam onto the charged surface of the image carrier to form an electrostatic latent image on the image carrier according to the image data; a development device supplies toner to the electrostatic latent image formed on the image carrier to make the electrostatic latent image visible as a toner image; the toner image is directly transferred from the image carrier onto a recording medium or is indirectly transferred from the image carrier onto a recording medium via an intermediate transfer member; a cleaner then cleans the surface of the image carrier after the toner image is transferred from the image carrier onto the recording medium; finally, a fixing device applies heat and pressure to the recording medium bearing the toner image to fix the toner image on the recording medium, thus forming the image on the recording medium.
Such a fixing device may include a cylindrical metal member to heat the fixing device effectively to shorten a warm-up time or a time to first print (hereinafter also “first print time”). Specifically, the metal member provided inside a loop into which an endless fixing belt is formed, facing the inner circumferential surface of the fixing belt. The metal member is heated by a built-in or external heater so as to heat the fixing belt. A pressing roller presses against the outer circumferential surface of the fixing belt at a position corresponding to the location of the metal member inside the loop formed by the fixing belt to form a nip between the fixing belt and the pressing roller through which the recording medium bearing the toner image passes. As the recording medium bearing the toner image passes through the nip, the fixing belt and the pressing roller apply heat and pressure to the recording medium to fix the toner image on the recording medium.
For example, for a fixing device like that described in JP-2008-158482-A has an advantage of preventing faulty fixing even when the warm-up time and/or first print time are shortened to speed up the fixing process. However, for the fixing device, each of the cylindrical metal member and the fixing belt is thin, and the clearance between the metal member and the fixing belt is 1 mm or smaller, resulting in a low operability when the fixing belt is relatively moved toward the metal member in the axial direction of the fixing belt for assembly.